362
FXUS63 KIND 291700
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
100 PM EDT Tue Sep 29 2026

.KEY MESSAGES...

- Patchy fog possible this morning

- Warm and dry through mid week with temperatures well above normal

- Rain chances return late week into the early weekend

- Dry and substantially cooler weather expected next week

&&

.FORECAST UPDATE...
Issued at 958 AM EDT Tue Sep 29 2026

Look for quiet weather conditions through the afternoon as surface
high pressure remains in control across the Ohio Valley region. The
forecast remains in great shape with only minor adjustments needed.
Have increased the hourly temps by 1 deg F based on recent trends.
Also boosted wind gusts this afternoon a few mph with slightly
deeper mixing expected.

&&

.DISCUSSION (Today through Monday)...
Issued at 251 AM EDT Tue Sep 29 2026

Dry and warm weather will remain the rule across central Indiana
through mid week, as a surface and upper level ridge gradually push
eastward. Our next chances for precipitation will come late this
week into the weekend, courtesy of a slow-moving frontal system,
after which a substantial change to far more fall-like conditions
appears likely.

Clear skies and light winds under the surface high this morning
should produce at least some patchy fog across the area,
particularly just prior to daybreak. Isolated spots of dense fog
will be possible, mainly north. This fog will mix out in typical
diurnal fashion after sunrise.

Dry and warm conditions will continue through at least early
Thursday as a slow moving upper level low gradually absorbs the
remnants of Hurricane Polo and pushes eastward into the central
CONUS. The frontal boundary between this system and another large
upper low well to our northeast over the eastern Canadian provinces
will be held up both by this slow eastward progression and the
influence of the upper ridge over the Gulf Coast, but will
eventually sag into the area Thursday night into Friday, which is
when rain chances will be highest. Blend keeps low PoPs in the area
into Sunday, though given the latest model data this appears to be
far too long, and suspect that we`ll see this window shrink as the
week wears on.

A rumble of thunder or two cannot be ruled out at times, though for
the most part, just showers will be expected, though locally heavy
downpours will be at least a modest concern given precipitable water
values near climatological maximum thanks in part to the presence of
tropical moisture from the Polo remnants. Recent drier conditions
across central Indiana will help to limit hydrologic concerns,
however.

In the wake of the front, two areas of strong Canadian high pressure
will drop into the region, bringing substantially cooler air and a
return to dry conditions for much of the first full week of October,
with max temperatures down as much as 15-20 degrees and min
temperatures down a solid 10-15 degrees, a bit below seasonal
normals and far more fall-like than conditions experienced through
the first third of the Autumn season.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 100 PM EDT Tue Sep 29 2026

Impacts:

- None

Discussion:

VFR conditions will occur through the period. No fog is expected
overnight with increasing high cloud cover. Winds will be light S-SW
this afternoon become light S-SE overnight.

A grazing influence from a weak storm system currently over the
southern Plains will provide for some SCT-BKN mid level clouds
across the area Wednesday. There is some chance for light showers at
KLAF, but confidence is too low to warrant any inclusion in the TAF
at this time. Winds will become S-SW and increase to between 6-10
kts by midday with some gusts up to 15 kts possible during the
afternoon.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Crosbie
AVIATION...Crosbie
DISCUSSION...Nield